At close, the Sensex was down 887.64 points or 1.31 percent at 66,684.26, and the Nifty was down 234.20 points or 1.17 percent at 19,745.
Biggest losers on the Nifty included Infosys, Tech Mahindra, HCL Technologies, HUL and Reliance Industries, while gainers were L&T, ONGC, NTPC, SBI and BPCL.